An article appearing in the August 20 issue of the Journal of the American Medical Association may throw a bit of cold water on recent enthusiasm for the Atkins diet.
In this article, 141 children treated with a radical version of a low carbohydrate diet had significant increases in total cholesterol, LDL cholesterol, and triglyceride levels, and a drop in HDL cholesterol (the good cholesterol.) These children were placed on this radical diet as an experimental treatment for severe seizure disorders, and were maintained on the diet only for a relatively short duration - it is not thought that a temporary increase in lipids preclude the use this seizure therapy in children (since it appears effective.) But because the diet used in this study resembles the Atkins diet, the authors point out, their findings may have implications for the hundreds of thousands of Americans now merrily partaking of the Atkins diet.
DrRich comments:
There are at least three reasons why lipids may have increased in children, but (it appears) do not increase in adults placed on Atkins-like low carbohydrate diets. First, children are not adults, and their metabolism is different from that of adults. Second, the diet they were placed on was fairly radical, and stressed a lot of fat (90% of the caloric intake) as opposed to protein. Third, the total caloric intake in this study was high - so as to promote normal growth. (In contrast, adults on low carbohydrate generally avoid excess caloric intake, because their goal is not to gain but to lose weight.) Nonetheless, this study does lend a cautionary note to the surging interest in Atkins-like low carbohydrate diets.From early clinical trials studying low-carbohydrate weight-loss diets in adults, it appears that rather than increasing lipid levels, such diets have generally shown a favorable change in lipids. Results from such trials have encouraged former skeptics to endorse large-scale, randomized trials looking at the long-term outcomes of patients on low-carbohydrate diets. And while Atkins proponents are gaining more confidence daily that their favorite diet will eventually generate definitive scientific proof of efficacy and safety, it seems clear that not all therapy that reduces lipid levels turns out to yield favorable outcomes. The clearest example of this is hormone replacement therapy (HRT) for post-menopausal women. For years, doctors assumed that because of the favorable lipid changes HRT was protective of the heart. If anything, the big randomized trials showed the opposite.
While some degree of carbohydrate restriction is probably quite safe, the most prudent course for people interested in a low carb path to weight control would seem to be to restrict the "fast" carbohydrates - potatoes, breads, pasta, rice, etc. - but not the kinds of carbohydrates that clearly do some good (i.e., vegetables and fruits.)
